The present invention relates to a control, energy supply management and xe2x80x9cpower sharingxe2x80x9d concept for the drives and control units in aircraft seats.
In control units, drive units and other configuration changing elements of an aircraft seat, the following serious faults may arise: Loose or disconnected plug type or other connectors, cable breakage, short circuits to ground or to another supply line, failed control units and failure of drive units or input devices and control elements, respectively, which may e.g. be pushbuttons, switches, chip card readers, possibly with a display.
It is the object of the present invention to indicate a system in which the function of the control units, drive units or other configuration changing elements is ensured.
This object is achieved according to the invention by the features of the independent patent claims.
Advantageous developments of the invention are characterized in the dependent claims.
The invention provides a redundancy concept which is fault tolerant. Advantageously, the concept is supplemented by a xe2x80x9cpower sharing and managementxe2x80x9d system for adaptation to the corresponding control demands, which constitutes a very essential and independent inventive idea.
The system according to the invention consists of a number of drive units, control units and monitoring units that are adapted to the respective aircraft seat, said elements of at least two, preferably adjacent, aircraft seats being preferably arranged in the form of a bus topology or ring topology. The system, however, may also comprise the elements of three or more aircraft seats.
The bus topology may be a ring system or also a linear system. Dual buses which are laid in anti-parallel fashion are preferably used in linear structures.
Another, e.g. discrete, arrangement of the input and control elements is also possible.
The control units and the drive units of the group of seats consisting of two or more aircraft seats are equipped with local intelligence which permanently transmits the configuration to the monitoring system parts, the units being e.g. equipped with suitable sensors. The control units have a bus controller. The bus controllers of at least two control units are informed through the configuration reports about all processes within the system.
The control unit and the drive units of an aircraft seat are connected to the control unit and the drive units of at least one further aircraft seat, preferably via a bus topology or ring topology, in such a way that each drive unit is controllable via two connections by the associated two control units. When the standard bus connection between a drive unit and the associated control unit of the aircraft seat is interrupted, this is noticed via the local intelligence of the system components and reported to the other control unit through the bus connection of which the affected control unit is then controlled.
Moreover, according to the invention each drive unit of the two or more aircraft seats can be supplied with power by at least two power supply units. When the local intelligence in the system components detects that the standard current path of an aircraft seat is interrupted, as is the case with a disconnected plug-type or other connection and with cable breakage in the power supply, this is reported via the bus system to the two control units, whereupon the control operation is performed such that the current is taken over from the partner system. The current is preferably calculated in advance to make sure that the partner supply is not overloaded.
Preferably, the power supply lines are only supplied with power in case of need. This means that in case of a short circuit there is first of all no reaction. However, the control means (CBIT=Continuous Built-in Test) installed in the control unit supplies the supply lines with current at intervals for a short period of time of e.g. 100 ms to feed e.g. the electronic system of the drive units, but also for checking whether there is a short circuit in the line system. Upon detection of a short circuit, the alternative power supply of the partner system is switched to.
Alternatively, there may be a constant current monitoring, and when a limit is exceeded, there will be a switching-off operation.
In accordance with the above description the presence of an unintended external supply e.g. from the 28-V onboard network of the aircraft can be detected. In this case the system parts are instructed to react only to the partner supply.
In case of a short circuiting to ground or to the supply of the bus system, the bus communication is interrupted. This will be noticed immediately, and the partner system will be switched to.
According to the present invention the failure of a control unit can also be compensated for. The status of each control unit and the demands made on the control task are exchanged between the control units. The status is here compiled and communicated on the basis of the CBIT. In the absence of plausible information from one control unit, the other control unit takes over the tasks of the partner. The xe2x80x9cpower managementxe2x80x9d in the control unit ensures that the power supply is not overloaded. If only the control unit has failed, the power supply can still be exploited.
Failure of an individual drive unit or a control element cannot be ruled out. Since these devices are in general not dual-redundant, such a failure must be tolerated. Manual feedback means are provided for such purposes in the drive units and the actuator systems, respectively. In the case of the input device and the control element, respectively, the device of the partner can however be used. The function of all of the other system components is not affected by such faults.
In the area of the aircraft seats a plurality of devices must be supplied with current. These are e.g. a video entertainment system, a telephone, and an internet access, the supply for a personal computer (laptop) and reading light as well as seat control.
Due to the number of aircraft seats the current per seat is bound to be limited. The present invention exploits the cross link between the seats to offer more power to the individual seat than can normally be obtained under worse case conditions. Since the instantaneously consumed current of the partner seat(s) is known, such an increase in power can be realized via the connection lines.
Moreover, according to the invention less important supplies are automatically switched off in heavy-duty cases. A special case is the demand to move the seat from all configurations into the landing configuration within 15 seconds. Calculations show that the power offered is not sufficient in such a case.
The present invention offers the possibility that unnecessary consumers are first switched off. This may e.g. be the reading light, video or personal computer.
In addition, according to the invention the partner system(s) is(are) also queried as to which amounts of current can be provided for support. In the case of such an xe2x80x9cemergency queryxe2x80x9d, the unnecessary consumers are also switched off in the partner system.
According to the present invention the predetermined limits can be observed both with respect to the actuator speeds and the maximum current intensities.